1. Field of the Invention
This invention relates generally to coated fasteners, and more particularly to a fastener, such as a staple or a nail, having a coating composed of 100% dry solids which is virtually free of solvent emissions when applied and during curing, covers substantially the entire exterior of the fastener, protects the fastener against corrosion, is capable of adhering successive fasteners together into a strip or block, and provides improved retention of the fastener when driven into a desired surface.
2. Description of the Related Art
Fasteners are typically coated to protect the fastener from corrosion and to adhere a plurality of fasteners together into a strip or block for ease of handling with a fastener driving tool. An example of such a coated fastener is illustrated in U.S. Pat. No. 3,813,985 which discloses a coating composed of a nitrocellulose resin dissolved in an organic solvent. After the solvent is evaporated the coating adheres to the fastener and can be utilized to adhere successive fasteners into a strip.
Upon evaporation of the solvent in such coatings, however, a large amount of undesirable volatile compounds are emitted. To conform to existing government regulations, the emitted volatile compounds must be contained and properly disposed which adds significant costs to the process.
A nitrocellulose resin itself is also physically weak, especially in tension, and provides a relatively weak bond with the fastener, especially when the fastener is composed of steel. Thus, such a resin tends to flake off the fastener before and during application. Additionally, when a nitrocellulose coated fastener is subjected to a removal force, either the bond between the resin and the fastener fails or the resin itself fractures.
It therefore would be desirable to provide a fastener having a coating composed of 100% dry solids which is virtually free of solvent emissions when applied and during curing, is strong in tension, covers substantially the entire exterior surface of the fastener, provides increased bonding to the fastener, protects the fastener against corrosion, adheres successive fasteners together in a strip, and provides increased retention of the fastener when driven into a desired surface.